1. Field of the Invention
The present invention relates to a surface emitting semiconductor laser.
2. Description of the Related Art
Document 1 (N. Nishiyama et al., IEEE Journal of Selected Topics in Quantum Electronics., vol. 11, no. 5, pp. 990-998, 2005.) discloses a tunnel junction surface emitting laser. An AlGaInAs/InP semiconductor distributed Bragg reflector and an n-type spacer layer are provided on a substrate. A semiconductor mesa is provided on the distributed Bragg reflector and includes an active layer, a tunnel junction region, and an InP spacer layer grown over the tunnel junction region. A dielectric distributed Bragg reflector is provided on the semiconductor mesa. An electrode is provided so as to surround the dielectric distributed Bragg reflector on the semiconductor mesa, and another electrode is provided so as to surround the semiconductor mesa on the n-type spacer layer.
Document 2 (K. L. Lear et al., IEEE Photonics Technology Letters., vol. 6, no. 7 , pp. 778-781, 1994.) discloses an surface emitting laser formed by using ion implantation. This surface emitting laser includes an n-type semiconductor mirror with 33-pair of layers, an active layer including three well layers, and a p-type semiconductor mirror with 22-pair of layers, which are arranged on a GaAs substrate. An electrode has a circular opening, and is provided on the p-type semiconductor mirror, which includes a cylindrical region that is located just below the opening, and the outer region that surrounds the cylindrical region. In the p-type semiconductor mirror, ions are implanted into the outer region. The ion implantation can provide a part of the p-type semiconductor mirror with high-resistance, and this part of high-resistance confines electric current.